As you may know, LeoCAD is a free, open-source, cross platform CAD software that permits you to create new models by using Lego bricks.
Among others, it is easy to use, has an intuitive interface and has many features that enables everybody to build CAD models. It is fully compatible with LDraw and has almost 10,000 different parts and continues to receive updates.
The latest version available is LeoCAD 18, which has been released a while ago.
The latest version of Leocad is available via the default repositories on Ubuntu 18.10 Cosmic Cuttlefish, Ubuntu 18.04 Bionic Beaver, Linux Mint 19.x, Linux Mint 18.x, Elementary OS 0.5 Juno and other Ubuntu derivative systems, so installing it on your Linux computer is easy.
All you need to do to update the local repository index and install the leocad package:
$ sudo apt-get update
$ sudo apt-get install leocad
Optional, to remove leocad, do:
$ sudo apt-get remove leocad